Photographic products, processes and compositions employing azo dye developers



United States Patent O 3,142,565 PHOTOGRAPHIC PRODUCTS, PROCESSES ANDCOMPOSITIONS EMPLOYING AZO DYE DEVELOPERS Elkan R. Blout, Belmont,Milton Green, Newton Center,

Howard G. Rogers, Weston, and Myron S. Simon, Newton Center, Mass,assignors to Polaroid Corporation, Cambridge, Mass., a corporation ofDelaware No Drawing. Filed Sept. 10, 1962, Ser. No. 222,656 29 Claims.(Cl. 96-29) This invention relates to photography and more particularlyto products, compositions and processes for the development ofphotosensitive silver halide elements.

It is one object of the present invention to provide novel processes andcompositions for the development of silver halide emulsions, in whichnovel colored developing agents are used.

Another object is to provide novel processes and compositions for thedevelopment of silver halide emulsions, in which the novel developingagent is capable of developing an exposed silver halide emulsion andimparting a reversed or positive colored image of the developed image toa superposed image-receiving material.

A further object is to provide novel silver halide devel oping agentsand novel products, processes and compositions suitable for use inpreparing monochromatic and multichromatic photographic images.

Other objects of the invention will in part be obvious and will in partappear hereinafter.

The invention accordingly comprises the processes involving the severalsteps and the relation and order of one or more of such steps withrespect to each of the others, and the products and compositionspossessing the features, properties and the relation of elements whichare exemplified in the following detailed disclosure, and the scope ofthe application of which will be indicated in the claims.

The objects of this invention may be accomplished by the use of certainnovel dyes which have the ability to develop images present in anexposed silver halide emulsion; thus they may be referred to as dyedevelopers. These novel dyes or dye developers will be further describedhereinafter.

For a fuller understanding of the nature and objects of the invention,reference should be had to the following detailed description.

The photographic processes and compositions disclosed herein areparticularly useful in the treatment of an exposed silver halideemulsion, whereby a positive dye image may be imparted to anotherelement, herein referred to as an image-carrying or image-receivingelement.

US. Patent No. 2,983,606, issued May 9, 1961 to Howard G. Rogers,discloses diffusion transfer processes wherein a photographic negativematerial, such as a photographic element comprising an exposed silverhalide emulsion, is developed in the presence of a dye developer toimpart to an image-receiving layer a reversed or positive dye image ofthe developed image by permeating into said emulsion a suitable liquidprocessing composition and bringing said emulsion into superposedrelationship with an appropriate image-receiving layer. The inventiveconcepts herein set forth provide novel dye developers for use in suchprocesses.

In carrying out the process of this invention, a photosensitive elementcontaining a silver halide emulsion is exposed and wetted with a liquidprocessing composition, for example by immersing; coating, spraying,flowing, etc., in the dark, and the photosensitive element superposedprior to, during or after Wetting, on an imag-receiving element. In apreferred embodiment, the photosensitive element contains a layer of dyedeveloper, and the liquid processing composition is applied-to thephotoice sensitive element in a uniform layer as the photosensitiveelement is brought into superposed position with an imagereceivingelement. The liquid processing composition permeates the emulsion toprovide a solution of dye developer substantially uniformly distributedtherein. As the exposed silver halide emulsion is developed, theoxidation product of the dye developer is immobilized or precipitated insitu with the developed silver, thereby providing an imagewisedistribution of unoxidized dye developer dissolved in the liquidprocessing composition. This immobilization is apparently due, at leastin part, to a change in the solubility characteristics of the dyedeveloper upon oxidation, and especially as regards its solubility inalkaline solutions. It may also be due, in part, to a tanning effect onthe emulsion by the oxidized developing agent. At least part of thisimagewise distribution of unoxidized dye developer is transferred, byimbibition, to a superposed image-receiving layer. The image-receivinglayer receives a depthwise diffusion, from the emulsion, of unoxidizeddye developer, without appreciably disturbing the imagewise distributionthereof, to provide a reversed or positive, colored image of thedeveloped or negative image. The image-receiving element may containagents adapted to mordant or otherwise fix the diffused, unoxidized dyedeveloper. Imbibition periods of approximately one minute have beenfound to give good results, but this contact period may be adjustedwhere necessary to compensate for variations in temperature or otherconditions. The desired positive image is revealed by stripping theimage-receiving layer from the silver halide emulsion at the end of theimbibition period.

The dye developers of this invention may be utilized in thephotosensitive element, for example in, on or behind the silver halideemulsion, or they may be utilized in the image-receiving element or inthe liquid processing composition. In a preferred embodiment, a coatingor layer of the dye developer is placed behind the silver halideemulsion, i.e., on the side of the emulsion adapted to be located mostdistant from the photographed subject when the emulsion is exposed andpreferably also adapted to be most distant from the image-receivinglayer when in superposed relationship therewith. Placing the dyedeveloper behind the emulsion layer, as in the preferred embodiment, hasthe advantage of providing increased contrast in the positive image, andalso minimizes any light-filtering action by the colored dye developer.In this preferred embodiment, the layer of dye developer may be appliedby using a coating solution containing about 0.5 to 8%, by weight, ofthe dye developer. Similar concentrations may be used if the dyedeveloper is utilized as a component of the liquid processingcomposition. In an especially useful mode of disposing the dyedevelopers in the photosensitive elements, the dye developer isdissolved in a water-immiscible solvent and then dispersed in a gelatincoating solution.

The liquid processing composition which is used in the processes hereindiscolsed comprises at least an aqueous solution of an alkalinecompound, for example, diethylamine, sodium hydroxide or sodiumcarbonate, and may contain the dye developer. In some instances, it maycontain an additional silver halide developing agent. If the liquidprocessing composition is to be applied to the emulsion by being spreadthereon, preferably in a relatively thin, uniform layer, it may alsoinclude a viscosityincreasing compound constituting film-formingmaterial of the type which, when spread over a water-absorbent base,will form a relatively firm and relatively stable film. A preferredfilm-forming material is a high molecular weight polymer such as apolymeric, water-soluble ether inert to an alkali solution, as, forexample, a hydroxyethyl cellulose or sodium carboxymethyl cellulose.Other filmforming materials orfthickening agents whose ability toincrease viscosity is substantially unaffected when left in solution fora long period of time may also be used.

The dye developers of this invention may be represented by the formula:(A) Z.

Y-fiR-J 1r-N=N(XaN=N)m X wherein Ar is an aryl nucleus, such as abenzene or naphthalene nucleus; each Z is an alkoxy group, preferably alower alkoxy group such as methoxy, ethoxy, etc., an alkyl group,preferably a lower alkyl group such as methyl, ethyl, etc., a hydroxylgroup, or a halogen group such as chlorine; m is or 1; n is 0 or apositive integer from 1 to 4, inclusive; p is 1 or 2; R is an alkylenegroup, preferably containing no more than 5 carbon atoms; Y is ap-dihydroxyphenyl or o-dihydroxyphenyl group, and alkyl and halogensubstituted derivatives thereof; X,, and X are each the radical of acoupling component, which coupling component may be the same ordifferent. By the expression coupling component, as used in the aboveformula and hereinafter, is meant a compound capable of being coupledinto by a diazonium salt, i.e., an azo coupler.

In a preferred embodiment, the aryl nucleus is a benzene nucleus and pis 1.

As illustrations of suitable azo coupling components or couplers fromwhich X and X may be derived, mention may be made of phenols andaromatic amines having a free position ortho or para to the hydroxyl oramino group, e.g., phenol, anilines, naphthols, anthrols,naphthylamines, etc.; heterocyclic aromatic compounds containinghydroxyl or amino groups, such as pyrazolones or pyrroles; aliphatic oralicyclic activated methylene couplers, i.e., compounds having analiphatic or alicyclic methylene group activated by two adjacent keto,aldehyde, ester or nitrile groups, which may be the same or different,or a keto, aldehyde, ester or nitrile group in combination with an amidegroup; e.g., 1,3-diketones or fl-ketonic acid arylamides, etc., andsubstituted derivatives thereof. Examples of groups which may be presentin such substituted derivatives include alkyl, sulfo, alkoxy, aryl,aryloxy, amino, keto, alkylamino, arylamino, hydroxyl, cyano,alkylamido, arylamido, carbalkoxy, carbox-amido, sulfonamido, etc.

As used herein with reference to X and X the expression radical of aphenolic coupler is intended to refer to hydroxyphenyl, hydroxynaphthyl,hydroxyanthryl, etc. radicals, and substituted derivatives thereof; theexpression radical of an aromatic amino coupler is intended to refer toaminophenyl, aminonaphthyl, etc. radicals, and substituted derivativesthereof; and the expressions radical of a heterocyclic aromatic coupler,radical of an aliphatic activated methylene coupler and radical of analicyclic activated methylene coupler are to be similarly construed.

The novel dye developers of this invention may be prepared bydiazotizing a compound of the formula:

wherein Y, R, Ar, Z, n, X and m have the same meaning as above, andcoupling diazotized compound (B) into the desired coupling componentproviding X As examples of useful intermediates within the scope ofFormula B, mention may be made of the followingp-(2,5-d1hydroxyphenucy1) aniline 2-( 5- [2,5-dimethoxy-3'-(2",5"-dimethoxy-3"-amlnopheny1- azo) -phenyl] propionyl -hydroquinone2- ['Y- amino phenyl) -butyryl] -hydr0quin one 0 CH CH3 0 CH 2-[5-2,5'-d.imethoxy-3-amino-pl1eny1) -a-methy1- propionyl] -hydroqulnone 2-['y- (4-omino-phenyl) -a-ethyl-butyryl] -hydroquinone 2- [5-(2-amino-phenyl) -valeryl] -hydroqninone 2- [B- 3Z4-dimethoxy-6-amino-phenyl) -propionyl] hydroquinone O C H;

on OCH;

on 0 on.

2- [B- (2',5'-dimethoxy-3-amino-phenyl) -a-methyl-prop1onyl]6-methy1-l1ydroqulnone O CH; 0 a I 6chloro-2- [fl-(2',5-dimeth'oxy-3-amino-phenyl) -a-methylpropionyl] -hydroquinone@iJ-CHP l-amino-i- 2',5-dihydroxyphenacyl) -naphtha1ene r-RCOOH e.g.,phenylacetic acid, naphthylacetic acid, their homologues and theiranalogues, to form the nitroaryl analogue; (b) forming the acid chlorideof the said analogue; (c) forming the hydroquinone derivative by theFriedel-Crafts reaction; and (d) reducing the nitro group (preferably inan acid medium) to form the compound of Formula B.

The compounds of Formula B wherein m is 0 may also be prepared accordingto the procedure disclosed in the copending application of Elkan R.Blout and Myron S. Simon, Serial No. 165,006, filed January 8, 1962, andwhich is a continuation-in-part of Serial No. 685,066, filed September20, 1957. If desired, the hydroxyl groups may be protected duringreaction by the use of suitable protective derivatives, e.g., O-acetylderivatives, according to the procedure disclosed in the aforementionedcopending application. However, it is also contemplated to effectdiazotization of the compounds of Formula B where the hydroxyl groupsare free. Where desired, the monoazo intermediates may be employed forfurther diazotization without removal of the protective groups.

Where desired, the compounds of Formula B may be 7 employed in the formof acid addition salts, e.g., the hydrochloride.

The coupling is generally performed at a pH which is preferably notgreater than about 9. The hydroxy groups of Y may be protected duringdiazotization and coupling, as by the use of O-acetyl derivatives asmentioned above.

By the use of two mols of the diazonium salt to each mol of the couplingcomponent, one may couple twice into certain of the coupling componentswhich provide the residue X as, for example, hydroxy and amino aromaticcompounds which have two directing groups and two free couplingpositions as, for example, 1,5-dihydroxynaphthalene. It may be notedthat such bis coupling may give rise to a mixture of dye developers, andsuch mixtures may be used in the processes of this invention.

Where the coupling component is a phenolic coupler, and particularly anaphthol, it has been found that coupling ortho to the hydroxyl groupgives a dye developer of superior color properties. It has also beenfound that such ortho-coupled dye developers exhibit essentially no pHsensitivity over a fairly wide range on either side of neutral.

As examples of suitable dye developers within the 6 scope of thisinvention, mention may be made of the following:

OH OH OCH OH OCH; OCH;

OH OOHs 4 methoxy-2-[2,5-dimeth'oxy-4-(2",5"-dimethoxy-3-[2"'-(2"",5"-dihydroxybenzoyl) ethyl] phenylazo)-phenylazo]-1-naphthol Thecoupling component employed to provide the residue X is preferably acoupler containing a diazotizable amino group. It is to' be understood,however, that one may employ a coupler having a group convertible to adiazotizable amino group, e.g., a nitro group. The

diazotizable amino group may be on a nucleus other than the onesubstituted by the azo grouping.

As examples of additional coupling components Which may be used toprovide X mention may be made of:

4-benzyl-1-naphthol 4-methyl-1-naphthol 4-methoxy-a-naphthylamine4-acetamido-m-naphthylamine Phenol Aniline 1,5-naphthalenediaminep-Cresol l-hydroxyanthracene 1-hydroxy-2-naphthanilide DiketohydrindeneMalononitrile Acetoacetanilide The novel dye developers of thisinvention are to be distinguished from the compounds disclosed andclaimed in the copending application of Elkan R. Blout, Milton Green andHoward G. Rogers, Serial No. 144,816, filed October 18, 1961, as acontinuation-impart of Serial No. 612,045 filed September 25, 1956 (nowabandoned), by the presence of the acyl group, i.e., the a group. Thepresence of the acyl group lowers the developing potential of the dyedeveloper and the resulting dye developer, in the absence of anauxiliary or accelerating developing agent, is relatively unreactive,and thereby results in a useful synergistic developing agent which isessentially unreactive during storage, e.g., when the dye developer isdisposed in the photosensitive element prior to exposure of saidelement.

The following examples of the preparation of dye developers within thescope of this invention by coupling compounds within Formula B are givenfor purposes of illustration only:

Example 1 (0.01 mol) of 2-['y-2,5'-dimethoxy-3'-amino-pl1enyl)-propionyl]-hydroquinone hydrochloride was dissolved in 200 cc. of 6 N.hydrochloric acid and a solution of (0.01 mol) of sodium nitrite in 15cc. of water. The mixture was stirred for approximately 15 minutes whilebeing cooled to about C., filtered through Celite, allowed to stand forapproximately 30 minutes, and added to a solution of (0.0086 mol) of4-methoxy-1-naphthol in 100 cc. of water and 120 cc. of pyridine. 20%sodium carbonate solution was added intermittently to retain the pH at 7to 8. After approximately one hour the slurry was filtered, washed withaqueous acetic acid, then washed with water and purified byprecipitation from methyl Cellosolve with 1% hydrochloric acid solution.The resultant 4-methoxy-2-(2',5'-dimethoxy-3-[2"-(2"',5"'-dihydroxybenzoyl)-ethyl] phenylazo) 1 naphthol [Formula spectralabsorption curves shows a )t at 530 mg in acetone, e=19,600

Example 2 2- ['y-(2.,5'-dimethoxy-3-amino phenyl) propionyl]-hydroquinone hydrochloride was diazotized in a manner similar to thatdescribed in Example 2 and coupled with 1-phenyl-3-methyl-5pyrazolone.The resultant product was 1-phenyl-3-methyl-4-(2,5' dimethoxy-3'-[2"-(2,5"-dihydroxybenzoyl)-ethyl] phenylazo)-S-pyrazolone [Formula 16]. Thespectral absorption curve showed a A at 410 me in methyl Cellosolve,e=19,400.

Example 3 2-(7-[2',5' dimethoxy 3' (2",5" dimethoxy-3"-aminophenylazo)-phenyl] propionyl)-hydraquinone hydrochloride wasdiazotized in a manner similar to that described in Example 2 andcoupled with 4-methoxy-1- naphthol. The resultant product was4-methoxy-2-[2',5- dimethoxy-4'-(2",5"-dimethoxy-3"-[2"'-(2"",5"dihydroxybenzoyl) ethyl] phenylazo) phenylazo]-l-naphthol [Formula 17].The spectral absorption curve showed a A,,,,,,, at 590 m in methylCellosolve, e=14,400.

In the same manner as described in the foregoing examples,4-[p-(2,5'-dihydroxyphenacyl) phenylazo]-3- (N-n-hexylcarbamyl) 1 phenyl5 pyrazolone [Formula 13] and2-[p-(2,5'-dihydroxyphenacyl)-phenylazo]-4-methoxy-l-naphthol [Formula14] were prepared by coupling diazotizedp-(2,5-dihydroxyphenacyl)-aniline with the azo coupler moiety of thecompound.

8 Example 4 hydroxybenzoyl) -ethyl] -phenylazo) -1-naphthol [Formula 15as prepared in Example 1] in a 4% solution of cellulose acetate hydrogenphthalate in a 50:50 mixture, by volume, of acetone and tetrahydrofuran.After this coating had dried, a silver iodobromide emulsion was applied.This photosensitive element was exposed and processed by spreading anaqueous liquid processing composition comprising:

Percent Sodium carboxymethyl cellulose 6.0 1-phenyl-3-pyrazolidone 0.2Sodium hydroxide 5.0 Potassium bromide 0.5

A photosensitive element was prepared similar to that described inExample 4 using 3% of l-phenyl-3-methyl- 4-(2',5'dimeth0xy-3'-[2"-(2"',5" dihydroxybenzoyl)- ethyl]-phenylazo)-5-pyrazolone [Formula 16 as prepared in Example 2], This photosensitiveelement was exposed and processed by spreading an aqueous liquidprocessing composition comprising:

Percent Sodium carboxymethyl cellulose 4.5 1-phenyl-3-pyrazolidone 0.2Sodium hydroxide 3.0 Potassium bromide 0.2

between said photosensitive element and an imagereceiving element assaid elements were brought into superposed relationship. Theimage-receiving element comprised a cellulose-coated baryta paper whichhad been coated with a solution comprising 10% Nylon Type F 8 (tradename of E. I. du Pont de Nemours & Co., Wilmington, Delaware forN-methoxymethyl polyhexamethylene adipamide) in aqueous ethanol. Afteran imbibition period of approximately one minute, the image-receivingelement was separated and contained a yellow positive dye image of thephotographed subject.

Example 6 A photosensitive element was prepared similar to thatdescribed in Example 4 using 3% of 4-methoxy-2-[2',5'- dimethoxy 4(2",5"-dimethoxy 3" [2-(2",5""- dihydroxybenzoyl) ethyl] phenylazo)phenylazo]-1- naphthol [Formula 17 as prepared in Example 3]. Exposureand processing with a liquid processing composition and image-receivingelement similar to those described in Example 4 gave a tan positive dyeimage of the photographed subject.

Example 7 A photosensitive element was prepared similar to thatdescribed in Example 4 using 3% of 4-[p-(2,5'-dihydroxyphenacyl)phenylazo] 3 (N-n-hexylcarbamynl-phenyLS-pyrazolone [Formula 13].Exposure and processing with a liquid processing composition andimage-receiving element similar to those described in Example 4 gave ayellow positive dye image.

Example 8 A photosensitive element was prepared similar to thatdescribed in Example 4 using 3% of 2-[p-(-2',5-dihydroxyphenacyl)phenylazo] 4 methoxy 1 naphthol [Formula 14]. Exposure and processingwith a liquid processing composition and image-receiving element similarto those described in Example 4 gave a magenta positive dye image.

Repeating the procedures of Examples 4, 5 and 6 without the auxiliarydeveloping agent results in positive dye images which exhibit poorcontrast and colored highlights, thus indicating that the dye developerin the exposed areas of the light-sensitive element is not oxidizedrapidly enough to control the transfer of said dye developer from theexposed areas to a superposed imagereceiving layer.

The dye developers of this invention are also useful in integralmultilayer photosensitive elements for use in multicolor diffusiontransfer processes. As an example of such photosensitive elements,mention may be made of the photosensitive elements disclosed and claimedin the copending US. application of Edwin H. Land and Howard G. Rogers,Serial No. 565,135, filed February 13, 1956, wherein at least twoselectively sensitized photosensitive strata are superposed on a singlesupport and are processed, simultaneously and without separation, with asingle common image-receiving element. A suitable arrangement of thistype comprises a support carrying a red-sensitive silver halide emulsionstratum, a green-sensitive silver halide emulsion stratum and ablue-sensitive silver halide emulsion stratum, said emulsions havingassociated therewith, respectively, a cyan dye developer, a magenta dyedeveloper and a yellow dye developer. In one of the preferredembodiments of photosensitive elements of this type, the dye developersare disposed in separate alkali-permeable layers behind thephotosensitive silver halide emulsion stratum with which they areassociated.

The photosensitive elements within the scope of this invention may beused in roll film units which contain a plurality-of photosensitiveframes. The photosensitive elements of this invention are especiallyuseful in composite roll film intended for use in a Polaroid LandCamera, sold by Polaroid Corporation, Cambridge 39, Massachusetts, or asimilar camera structure such, for example, as the camera forming thesubject matter of US. Patent No. 2,435,717, issued to Edwin H. Land onFebruary 10, 1948. In general, such composite roll films comprise aphotosensitive roll, a roll of imagereceiving material and a pluralityof pods containing an aqueous alkaline processing solution. The rollsand pods are so associated with each other that, upon processing, thephotosensitive element may be superposed on the image-receiving elementand the pods may be ruptured to spread the aqueous alkaline processingsolution between the superposed elements. The nature and construction ofthe pods used in such units are well known to the art. See, for example,US. Patents Nos. 2,543,181 and 2,634,886, issued to Edwin H. Land.

It will be noted that the liquid processing composition may contain oneor more auxiliary or accelerating silver halide developing agents, suchas p-methylaminophenol (Metol); 2,4-diaminophenol (Arnidol);benzylaminophenol; hydroquinone; a substituted hydroquinone such astoluhydroquinone, phenylhydroquinone, or 4-methylphenylhydroquinone; ora 3-pyrazolidone such as 1- phenyl-3-pyrazolidone. These silver halidedeveloping agents are substantially colorless, at least in theirunoxidized form. It is possible that some of the dye developer oxidizedin exposed areas may be oxidized by an energy transfer reaction withoxidized auxiliary developing agent.

In addition, development may be effected in the presence of an oniumcompound, particularly a quaternary ammonium compound, in accordancewith the processes disclosed and claimed in the copending application ofMilton Green and Howard G. Rogers, Serial No. 50,851, filed August 22,1960.

The dye developers of this invention may be used also in conventionalphotographic processes, such as tray or tank development of conventionalphotosensitive fihns, plates or papers to obtain black-and-white,monochromatic or toned prints or negatives. By way of example, adeveloper composition suitable for such use may comprise an aqueoussolution of approximately 12% of the dye developer, 1% sodium hydroxide,2% sodium sulfite and 0.05% potassium bromide. After development iscompleted, any unreacted dye developer is washed out of thephotosensitive element, preferably with an alkaline washing medium orother medium in which the unreacted dye developer is soluble. Theexpression toned is used to designate photographic images wherein thesilver is retained with the precipitated dye, whereas monochromatic isintended to designate dye images free of silver.

It should be noted that the dye developers of this medium areself-suflicient to provide the desired color image and do not dependupon coupling reactions to produce the desired color. They thus providea complete departure from conventional photographic color processes inwhich the color is producedby a coupling reaction between a color formeror coupler and the oxidized developing agent, as well as so-calledauto-coupling processes in which color is obtained by a reaction of theoxidized developing agent with unoxidized developing agent.

It will be apparent that, by appropriate selection of theimage-receiving element from among suitable known opaque and transparentmaterials, it is possible to obtain either a colored positive reflectionprint or a colored positive transparency. Likewise, the inventiveconcepts herein set forth are adaptable for multicolor work by the useof special photographic materials, for example, film materials of thetype containing two or more photosensitized elements associated with anappropriate number of image-receiwng elements and adapted to be treatedwith one or more liquid processing compositions, appropriate dyedevelopers suitable to impart the desired subtractive colors beingincorporated in the photosensitized elements or in the liquid processingcompositions. Examples of such photographic materials are disclosed inUS. Patent No. 2,647,049 to Edwin H. Land.

As examples of useful image-receiving materials, mention may be made ofnylon, e.g., N-methoxymethyl-polyhexamethylene adipamide, polyvinylalcohol, and gelatin, particularly polyvinyl alcohol or gelatincontaining a dye mordant such as poly-4-vinylpyridine. Theimage-receiving element also may contain a development restrainer, e.g.,1-phenyl-S-mercaptotetrazole, as disclosed in the copending applicationof Howard G. Rogers and Harriet W. Lutes, Serial No. 50 ,849, filedAugust 22, 1960.

The dye developers herein set forth are also useful in theformation ofcolored images in accordance with the photographic products andprocesses described and claimed in US. Patent No. 2,968,554, issued toEdwin H. Land on January 17, 1961.

The novel compounds herein disclosed are also suitable for use as dyesfor textile fibres, such as nylon.

In the preceding portions of the specification, the expression color hasbeen frequently used. This expression is intended to include the use ofa plurality of colors to obtain black.

This application is in part a continuation of our copending application,Serial No. 685,081, filed September 20, 1957 (now abandoned).

Our copending US. application, Serial No. 222,702, filed concurrentlyherewith, claims the novel compounds of the present invention.

enemas Since certain changes may be made in the above products,compositions and processes without departing from the scope of theinvention herein involved, it is intended that all matter contained inthe above description shall be interpreted as illustrative and not in alimiting sense.

What is claimed is:

1. A novel photographic developer composition comprising an aqueousalkaline solution of a colorless silver halide auxiliary developingagent and an azo dye of the formula:

wherein Ar is an aryl nucleus; R is an alkylene group; Y is adihydroxyphenyl silver halide developing radical; X and X eachrepresents the radical of an azo dye coupler linked to said -N=N groupand completing said azo dye; and m is an integer from O to l, inclusive.

2. A novel photographic developer composition as defined in claim 1wherein X is a phenolic azo coupler radical.

3. A novel photographic developer composition as defined in claim 1wherein X is an aromatic amino azo coupler radical.

4. A novel photographic developer composition as defined in claim 1wherein X is a heterocyclic aromatic azo coupler radical.

5. A novel photographic developer composition as defined in claim 1wherein X, is selected from the group consisting of aliphatic andalicyclic activated methylene azo coupler radicals.

6. A novel photographic developer composition comprising an aqueousalkaline solution of 4-methoxy-2- (2',5' dimethoxy-3' [2"(2,5-dihydroxybenzoyl)- ethyl]-phenylazo)-1-naphthol and a colorlesssilver halide auxiliary developing agent.

7. A novel photographic developer composition comprising an aqueousalkaline solution of l-phenyl-B-methyl- 4 (2',5'dimethoxy-3'-[2"-(2',5"'-dihydroxybenzoyl)- ethyl] phenylazo) 5pyrazolone and a colorless silver halide auxiliary developing agent.

8. A novel photographic developer composition comprising an aqueousalkaline solution of 4-methoxy-2- [2,5'-dimethoxy-4'-(2,5"-dimethoxy-3"-[2"-(2,5""- dihydroxybenzoyl) ethyl]phenylazo) phenylazo]-1- naphthol and a colorles silver halide auxiliarydeveloping agent.

9. A novel photographic product comprising a support, a silver halideemulsion in a layer on said support, and a dye developer in a layer onthe same side of said support as said emulsion, said dye developercomprising an azo dye of the formula:

Y O-RAr-N=N (X n N=N m]X b l wherein Ar is an aryl nucleus; R is analkylene group; Y is a dihydroxyphenyl silver halide developing radical;X and X each represents the radical of an azo dye coupler linked to said-N=N group and completing said azo dye; and m is an integer from to 1,inclusive.

10. A novel photographic product as defined in claim 9 wherein saidproduct contains a colorless silver halide auxiliary developing agent ina layer on the same side of said support as said emulsion.

11. A novel photographic product comprising a support, a silver halideemulsion in a layer on said support and 4-methoxy-2-(2,5'dirnethoxy-3-[2"-(2",5-dihydroxybenzoyl)-ethyl]-phenylazo)-1-naphtho1 ina layer on the same side of said support as said emulsion.

12. A novel photographic product comprising a support, a silver halideemulsion in a layer on said support and l-phenyl 3 methyl 4(2,5'-dimethoxy-3-[2"- (2',5"'-dihydroxybenzoyl) ethyl] -phenylazo)--pyrazolone in a layer on the same side of said support as saidemulsion.

13. A novel photographic product comprising a support, a silver halideemulsion in a layer on said support and 4methoxy-2-[2,5'-dimethoxy-4'-(2",5"-dimethoxy- 3-[2"-(2",5"-dihydroxybeuzoyl)-ethyl]-phenylazo)- phenylazo]-l-naphthol in a layer onthe same side of said support as said emulsion.

14. In a process of forming a photographic image in color, the stepswhich comprise developing a latent image contained in an exposed silverhalide emulsion by contacting said emulsion with an aqueous alkalinesolution containing a colorless silver halide auxiliary developing agentand an azo dye developer of the formula:

wherein Ar is an aryl nucleus; R is an alkylene group; Y is adihydroxyphenyl silver halide developing radical; X and X eachrepresents the radical of an azo dye coupler linked to said -N=N groupand completing said azo dye developer; and m is an integer from 0 to 1,inclusive; oxidizing said dye developer in exposed areas to provide insaid emulsion a predetermined distribution of unoxidized dye developerand transferring at least part of said distribution of said unoxidizeddye developer by imbibition from said emulsion to an image-receivingelement in superposed relationship with said emulsion to impart to saidimage-receiving element a reversed, positive dye image of the developedimage.

15. A process as defined in claim 14 wherein X is a phenolic azo couplerradical.

16. A proces as defined in claim 14 wherein X is an aromatic amino azocoupler radical.

17. A proces as defined in claim 14 wherein X is a heterocyclic aromaticazo coupler radical.

18. The process as defined in claim 14 wherein X is selected from thegroup consisting of aliphatic andalicyclic activated methylene azocoupler radicals.

19. The proces as defined in claim 14 wherein said compound is 1 phenyl3-methyl-4-(2',5'-dimethoxy-3-[2- (2",5-dihydroxybenzoyl) ethyl]phenylazo) -5-pyrazolone.

20. The process as defined in claim 14 wherein said compound is 4methoxy 2 (2',5' dimethoxy-3-[2"- (2,5" dihydroxybenzoyl) ethyl]phenylazo) 1- naphthol.

21. The process as defined in claim 14 wherein said compound is 4methoxy 2 [2',5-dimethoxy-4'-(2",5"- dimethoxy3"-[2-(2",5"-dihydroxybenzoyl)-ethyl]- phenylazo -phenylazo]-l-naphthol.

22. A process of developing an exposed photosensitive silver halideemulsion which comprises contacting an exposed silver halide emulsionwith an aqueous alkaline solution containing a colorless silver halideauxiliary developing agent and an azo dye of the formula:

wherein Ar is an aryl nucleus; R is an alkylene group; Y is adihydroxyphenyl silver halide developing radical; X and X eachrepresents the radical of an azo dye coupler linked to said N=N-- groupand completing said azo dye; and m is an integer from 0 to 1, inclusive.

23. A process as defined in claim 22 wherein X is a phenolic azo couplerradical.

24. A process as defined in claim 22 wherein X, is an aromatic amino azocoupler radical.

25. A process as defined in claim 22 wherein X is a heterocyclicaromatic azo coupler radical.

26. The process as defined in claim 22 wherein X is selected from thegroup consisting of aliphatic and alicyclic activated methylene azocoupler radicals.

27. The proces as defined in claim 22 wherein said compound is l-phenyl3 methyl-4-(2',5-dimethoxy-3-[2"- (2",5"dihydroxybenzoyl)-ethyl]-phenylazo)-5-pyrazolone.

13 14 28. The process as defined in claim 22 wherein said ReferencesCited in the file of this patent compound iS 4-methoxy 2 (2',5 dimethoxy3' [2"- III !H .1 l 1 f i fi dlhydmxybenm) ethy] Pheny 1 2,983,606Rogers May 9, 1961 29. The process as defined in claim 22 wherein said 5FOREIGN PATENTS compound is 4-meth0xy-2- [2',5-dimethoxy-4-(2",5"-dimethoxy 3"-[2'-(i2,, 5"-dihydroxybenzoyl)-ethyl] 554212 Belgmm July1957 phenylazo -phenylazo] -1-naphth0l.

14. IN A PROCESS OF FORMING A PHOTOGRAPHIC IMAGE IN COLOR, THE STEPSWHICH COMPRISE DEVELOPING A LATENT IMAGE CONTAINED IN AN EXPOSED SILVERHALIDE EMULSION BY CONTACTING SAID EMULSION WITH AN AQUEOUS ALKALINESOLUTION CONTAINING A COLORLESS SILVER HALIDE AUXILIARY DEVELOPING AGENTAND AN AZO DYE DEVELOPER OF THE FORMULA: